Problem with Flash ExternalInterface on Google App Engine

后端未结

关注

 3  1423

I\'ve been struggling with this for the past couple hours now and I really don\'t know what could be wrong. I\'m simply trying to get Javascript to communicate text with Fla

相关标签:

3条回答

温柔的废话

2020-12-10 10:00

It probably doesn't have to do with Google app engine per se, since the whole thing's running in the browser -- unless there's some sort of server dependency somewhere you haven't mentioned. Assuming that's not the case...

If you're able to get Flash to call into JavaScript with ExternalInterface.call(), but not JavaScript to call back into Flash, then it's probably one or two things: your EI callback & handler aren't wired up properly (in Flash), or your JavaScript doesn't have a handle on the SWF object in the browser.

You might try posting some code, but in the meantime, here's something I know works in both IE and FireFox. First, the browser code:

<html>
<head>
<script language="JavaScript" type="text/javascript">

    var swfReady = false;

    function callbacksInitialized()
    {
        swfReady = true;
    }

    function helloFlash()
    {
        if (swfReady)
        {   
            // Get a handle on the Flash object
            var swfObject = navigator.appName.indexOf("Microsoft") != -1 ? window["HelloMac"] : document["HelloMac"] ;

            // Call back into the Flash file 
            swfObject.helloFlash(document.getElementById("txtMessage").value);
        }
    }

    function helloMac(message)
    {
        alert(message);
    }

</script>
</head>
<body scroll="no">
    <div align="center">

        <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
                id="HelloMac" width="600" height="300"
                codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">
                <param name="movie" value="HelloMac.swf" />
                <param name="quality" value="high" />
                <param name="bgcolor" value="#869ca7" />
                <param name="allowScriptAccess" value="sameDomain" />
                <embed src="HelloMac.swf" quality="high" bgcolor="#869ca7"
                    width="600" height="300" name="HelloMac" align="middle"
                    play="true"
                    loop="false"
                    quality="high"
                    allowScriptAccess="sameDomain"
                    type="application/x-shockwave-flash"
                    pluginspage="http://www.adobe.com/go/getflashplayer">
                </embed>
        </object>

        <br /><br />
        <input type="text" id="txtMessage" value="Hello, Flash!" /><br />
        <input id="btnSend" type="button" value="Send to Flash" onclick="helloFlash();" />
    </div>
</body>
</html>

And now, the Flash code (in my case, it's Flex, so hopefully it's clear):

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" initialize="init()" height="300" width="600">

    <mx:Script>
        <![CDATA[

            import mx.controls.Alert;
            import flash.external.ExternalInterface;

            private function init():void
            {
                addCallbacks(); 
            }

            private function addCallbacks():void
            {
                ExternalInterface.addCallback("helloFlash", this_helloFlash);
                ExternalInterface.call("callbacksInitialized");
            }

            // Display a message from the host
            private function this_helloFlash(message:String):void
            {
                Alert.show(message);
            }

            // Send a string to the host
            private function helloMac():void
            {
                if (ExternalInterface.available)
                {
                    ExternalInterface.call("helloMac", txtMessage.text);
                }
            }

        ]]>
    </mx:Script>

    <mx:VBox horizontalCenter="0" verticalCenter="0">
        <mx:TextInput id="txtMessage" text="Hello, Mac!" />
        <mx:Button id="btnSend" label="Send to Host" click="helloMac()" />
    </mx:VBox>

</mx:Application>

The example demonstrates Flash calling into JavaScript with some text, and JavaScript calling back into Flash in the same way. Some points to pay attention to:

Make sure you wait to call into Flash until Flash has notified the browser it's ready to begin receiving calls (as indicated by my callbacksInitialized() method).
Test to be sure you're using the appropriate browser-specific object reference (e.g., window["HelloMac"] vs. document["HelloMac"]).

Without knowing more, I'm guessing it's one of these two items, since that's been my experience. Hope it helps! I'll keep an eye on the post for follow-ups in case you have any.

0 讨论(0)

無奈伤痛

2020-12-10 10:14

Yup the answer by Christian Nunciato is helpful. The issue is that your swf file is not available to javascript at the time your javascript calls the flash function. Christian's trick makes sure the swf file is loaded and started when your javascript needs it.

0 讨论(0)
发布评论:

提交评论
- 加载中...
被撕碎了的回忆

2020-12-10 10:17

I do not see a call to the allowDomain function in your code. With out that the security sandbox will not allow your flash application to communicate with flash and vice versa on the server. Add a call to System.security.allowDomain("mydomain.com", "mySecondDomain.com", "etc.com") for every domain the flash app will be executed on. Also the embed code also needs to specify access for JavaScript by including the parameter <param name="allowScriptAccess" value="always" />.

0 讨论(0)
发布评论:

提交评论
- 加载中...